Received-SPF: pass (google.com: domain of linux-wireless-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Message-ID: <ca2b26a87d49284a07b24c71046993814c4fe821.camel@sipsolutions.net>
Subject: Re: iwlwifi: 8265: unexpected LLC packets TX'ed in monitor mode
From:   Johannes Berg <johannes@sipsolutions.net>
To:     Marco Fonseca <marco@tampabay.rr.com>,
        linux-wireless@vger.kernel.org
Date:   Mon, 25 May 2020 11:23:55 +0200
In-Reply-To: <20200513174827.3o7odouinuirou62@192.168.1.10> (sfid-20200513_195606_809894_A3639A1D)
References: <20200513174827.3o7odouinuirou62@192.168.1.10>
         (sfid-20200513_195606_809894_A3639A1D)
Content-Type: text/plain; charset="UTF-8"
User-Agent: Evolution 3.36.2 (3.36.2-1.fc32) 
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Sender: linux-wireless-owner@vger.kernel.org
Precedence: bulk

On Wed, 2020-05-13 at 13:48 -0400, Marco Fonseca wrote:
> Hello,
> 
> While in monitor mode, the 8265 will periodically transmit gratuitous
> LLC packets.  In this mode, I would expect the wifi chipset to not
> transmit any packets at all (unless packet injection is being used).
> 
> This behavior can be observed by a second wifi device in monitor mode.
> A display filter on wireshark/tshark of 'llc' makes these easy to spot.
> 
> It seems these packets only get produced in presence of a few APs
> and/or STAs but I'm not sure of the exact cause.  I don't see the LLC
> packets on very quiet channels.

I think these are somehow related to calibrations in the device.

johannes